1. Field of the Invention
This invention relates to refractory lined process equipment such as conduits in reactors, furnaces, cyclone separators, and the like, particularly where high temperature gases containing entrained solids are being processed. More particularly, the invention relates to improved end refractory anchors for such equipment and to insulated structures utilizing such anchors.
Refractory liners have been used for many years in process vessels, reactors, conduits, furnaces and the like to provide thermal insulation, and in environments such as fluidized catalytic reactors or regenerators or stacks, to provide resistance to abrasion or erosion. Such liners can serve not only to thermally insulate a shell or other surface but also to prolong its service life by shielding it from erosion by abrasion. In fluid catalytic cracking units for petroleum hydrocarbons, quite high fluid velocities which may be on the order of 50 to 70 ft/second occur, and the abrasive effect of entrained cracking catalyst is very pronounced. Moreover, high temperatures are involved. For example, in the regenerator the temperature of gases exiting through the cyclones may be on the order of 1250.degree.-1350.degree. F. and in the reactor the temperature may be 800.degree.-900.degree. F. Accordingly, the usual practice has been to line all vessels, conduits and cyclone separators through which fluid with entrained catalyst flows with refractory liner to prevent erosion of the metal surfaces and to provide thermal insulation. To retain the refractory, which may be a refractory cement, a concrete cement-aggregate mixture, or a reinforced cement or concrete, various anchoring arrangements have been employed. Some of the presently utilized anchoring arrangements work quite well on the main surfaces of the liners, but there have been problems with the portion of the liner adjacent the end of conduit outlets and the like.
2. The Prior Art
A common approach to protecting the outlet ends of refractory lined conduits has been the use of stop bars (retainers) welded to the outlet end of the conduits to support the liner. However, particularly in severe service conditions, these stop bars tend to disintegrate and become ineffective such that frequent repair or replacement has been necessary. There has been a need for an improved refractory anchoring system to protect lined conduit outlets. Such a system is provided by this invention.